Storage Tank with Annulus

ABSTRACT

A tank for retaining material includes a foundation, a shell, and an annulus. The foundation supports the material. The shell is partially embedded into the foundation and is configured to retain the material in a material storage area enclosed by the shell. The annulus is connected to the shell. A portion of the annulus extends beneath the material storage area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 63/246,440, filed Sep. 21, 2021, the entire contents of which are incorporated by reference herein.

BACKGROUND

The present disclosure relates to storage tanks, and particularly to above ground storage tanks which are used to store fluids of all types.

In the United States, minimum design loads and various other criteria for buildings and other structures are set forth in ASCE7. ASCE7 describes the means for determining loads for soil, flood, tsunami, snow, rain, atmospheric ice, earthquake, and wind, and their combinations for general structural design.

For example, these requirements include a seismic uplift requirement. Seismic uplift, in general, refers to upward vertical loads on a structure produced by lateral seismic accelerations that result in lateral loads applied to the structure above its base foundation due to structure inertia. These lateral loads attempt to overturn the structure resulting in downward loads on one side of the structure and uplift loads on the other. The uplift load produced by overturning is seismic uplift. Additional seismic uplift results from vertical seismic accelerations that result in vertical loads due to structure inertia. Current provisions in ASCE7 limit the seismic uplift to a level not to exceed the counteracting weight of materials above the foundation.

SUMMARY

In one aspect, a tank for retaining material is provided. The tank includes a foundation for supporting the material, a shell partially embedded into the foundation, and an annulus connected to the shell. The shell is configured to retain the material in a material storage area enclosed by the shell. A portion of the annulus extends beneath the material storage area.

In another aspect, when viewed in vertical cross-section, the lateral arm extends at about a right angle from the vertical arm.

In yet another aspect, the annulus includes an annular plate, the annular plate is embedded into the foundation, and the annular plate abuts the lateral arm and is positioned between the lateral arm and the material storage area.

In yet another aspect, the annular plate has an outermost diameter that abuts an innermost diameter of the vertical arm.

In yet another aspect, the shell is generally cylindrical, a curved wall of the shell extends vertically away from the foundation, and, when viewed in vertical cross section, the lateral arm extends from the shell in a direction away from a centerline of the generally cylindrical shell.

In yet another aspect, the annulus further includes an annular plate, the annular plate is connected to and abuts the lateral arm, and, when viewed in vertical cross section, the annular plate extends from the lateral arm, past the shell, and back towards the centerline.

In yet another aspect, the annular plate is formed integrally with the lateral arm.

In yet another aspect, the annulus is a first annulus, and when viewed in vertical cross-section, the first annulus includes a first vertical arm and a first lateral arm. The first vertical arm extends along and is connected to the shell and the first lateral arm extends away from the shell. The tank also includes a second annulus, and, when viewed in vertical cross-section, the second annulus includes a second vertical arm and a second lateral arm. The second vertical arm extends along and is connected to the shell, and the second lateral arm extends in a direction away from the shell that is different than the first lateral arm.

In yet another aspect, the shell is generally cylindrical, a curved wall of the shell extends vertically away from the foundation, and, when viewed in vertical cross section, the first lateral arm extends beneath the material storage area and the second lateral arm extends in a direction away from a centerline of the generally cylindrical shell.

In yet another aspect, when viewed in vertical cross-section, the first lateral arm has a longest dimension that is longer than a longest dimension of the first lateral arm.

In yet another aspect, the annulus is entirely embedded within the foundation, and an interface between the annulus and the shell is entirely embedded within the foundation.

In yet another aspect, a method of installing a tank includes connecting the annulus to the shell and embedding the annulus and a bottom portion of the shell into the foundation.

In yet another aspect, a tank assembly includes a shell enclosing an interior volume and an annulus. When viewed in vertical cross-section, the annulus includes a vertical arm and a lateral arm. The vertical arm extends along the shell, the lateral arm extends away from the shell, and the vertical arm is connected to the shell.

In yet another aspect, a method of installing a tank assembly includes connecting the annulus to the shell and embedding the annulus and a bottom portion of the shell into a foundation such that the shell forms sides of an area configured to retain material and the foundation forms a bottom of the area configured to retain material.

In yet another aspect, an annular plate is mechanically connected to the lateral arm and the annular plate extends further than the lateral arm toward the centerline of the shell.

In yet another aspect, the foundation comprises concrete.

In yet another aspect, the foundation is embedded into the ground.

Other aspects will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, section view of a tank.

FIG. 2 is another section view of the tank of FIG. 1 .

FIG. 3 is top plan view of the tank of FIG. 1 , and illustrates a cover on the tank shell.

FIG. 4 is a detailed plan view of a segment of the tank of FIG. 3 .

FIG. 5 is a detailed section view of the segment of the tank of FIG. 4 .

FIG. 6 is a detailed plan view of a segment of another embodiment of the tank of FIG. 3 .

FIG. 7 is a detailed section view of the segment of the tank of FIG. 6 .

FIG. 8 is a detailed plan view of a segment of another embodiment of the tank of FIG. 3 .

FIG. 9 is a detailed section view of the segment of the tank of FIG. 8 .

FIG. 10 is a detailed plan view of a segment of another embodiment of the tank of FIG. 3 .

FIG. 11 is a detailed section view of the segment of the tank of FIG. 10 .

Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Use of “including” and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of” and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

DETAILED DESCRIPTION

A tank 1 is shown in FIGS. 1-3 . The tank 1 includes a shell 5 and a foundation 10. The illustrated shell 5 and the foundation 10 are generally cylindrical about a centerline 3. A portion of the shell 5 extends into the foundation 10 about an entire circumference of the shell 5. This configuration is generally referred to as an embedded tank. A fluid 20 in the tank 1 exerts a fluid weight 22 in a “downward” direction substantially parallel to the centerline 3. The material stored in the tank is not limited to fluids or any specific fluid, as rock, grain, salt, granulate, and fluids having a wide range of viscosities could be stored in the tank. The shell 5 retains the fluid 20 laterally, i.e., in a direction substantially perpendicular to the centerline 3. The foundation 10 retains the fluid 20 vertically, i.e., in a direction substantially parallel to the centerline 3 and opposite of the direction of the fluid weight 22. In some embodiments, the shell 5 may be cylindrical, but the foundation 10 may be non-cylindrical (e.g., square, rectangular, oblong, irregular, and the like). Additionally, in other embodiments, the shell 5 may also be non-cylindrical.

The shell 5 is formed from steel, although a person of skill in the art will appreciate that the shell 5 can additionally or alternatively be formed from other materials. In some embodiments, for example as shown in FIG. 1 , the shell 5 is open such that the fluid 20 in the tank 1 is exposed to open air. In other embodiments, for example as shown in FIG. 3 , the shell 5 includes a shell covering 30 so that the fluid 20 in the tank 1 is not exposed to open air.

The foundation 10 sits on or is partially embedded into the ground 15. While the foundation 10 illustrated in FIGS. 1 and 2 is a slab 12 with a ring footing 13, the foundation can alternatively include only the slab 12, i.e., without the ring footing 13. The foundation 10 is formed from concrete, although a person of skill in the art will appreciate that the foundation 10 can additionally or alternatively be formed from other materials. In general, the tank 1 shown in FIGS. 1-3 thus results in a steel shell with a concrete floor.

An annulus 25 is provided around the portion of the shell 5 that is embedded into the foundation 10. The annulus 25 is fixed to the shell 5. In some embodiments, the annulus 25 is welded to the shell 5. In other embodiments, the annulus 25 is fixed to the shell 5 by rivets or other suitable mechanical fasteners. In still other embodiments, the annulus 25 is integrally formed as a single piece with the shell 5. The annulus 25 functions such that the fluid (or material) weight 22, which increases with increasing fluid (or material) depth 35, aids in reducing harm to the tank 1 caused by seismic uplift. As a result, the annulus 25 has a dramatic impact on the tank's 1 ability to resist seismic uplift. This, in turn, allows embedded concrete tanks to be used in a vastly larger number of applications and still comply with ASCE7 requirements.

Referring now to FIGS. 4 and 5 , the illustrated annulus 25 includes a vertical arm 40 and a lateral arm 45 connected by a rolled angle. The vertical arm 40 extends around an interior wall of the shell 5 and is substantially parallel to the shell 5 along the centerline 3 (not shown in the detailed views of FIG. 4 or 5 , but is shown in, for example, FIG. 1 ). The vertical arm 40 is connected to the interior wall of the shell 5. The lateral arm 45 extends from the vertical arm 40 toward the centerline 3. The angle between the vertical arm 40 and the lateral arm 45 is about 90 degrees (i.e., about a right angle), although other angles are contemplated. Together, the vertical arm 40 and the lateral arm 45 extend around the entire interior of the circumference of the shell 5. In other embodiments, the annulus 25 (including the vertical and lateral arms 40, 45) extends around less than the entire interior of the circumference of the shell 5. For example, the annulus 25 may only extend along two, four, eight, twenty, or 100 sectors along the interior of the circumference of the shell 5. The pressure from the fluid weight 22 acts on the lateral arm 45, which, via the vertical arm's 40 connection to the shell 5, acts to better retain the shell 5 within the foundation 10. As a result, the annulus 25 has a dramatic impact on the tank's 1 ability to resist seismic uplift. Because the lateral arm 45 extends toward the centerline 3 and is under the fluid weight 22, better resistance to seismic uplift is provided than even, for example, if the lateral arm 45 were to extend from the shell 5 away from the centerline 3.

The vertical arm 40 and lateral arm 45 shown in FIG. 5 have, in vertical cross section, a longest dimension that is equal or is substantially equal (i.e., the lengths are within 5%, or in other embodiments 1%, of one another). Stated otherwise, the length that the vertical arm 40 extends up the shell 5 is similar to the length that the lateral arm 45 extends away from the shell 5. However, other embodiments are contemplated. For example, in the embodiment shown in FIG. 11 , the annulus 25, in vertical cross section, has a lateral arm 45 with a longest dimension that is much longer than the longest dimension of the vertical arm 40. Other relative lengths of the vertical and lateral arms 40, 45 are contemplated. In some embodiments, the lateral arm 45 extends all the way across the bottom of the shell 5 to the opposing side of the shell 5. However, in other embodiments such as that shown in FIG. 5 , the lateral arm 45 does not extend all the way across the bottom of the shell 5. In some embodiments, the lateral arm 45 extends about 10% of an entire distance across the bottom of the shell 5. In other embodiments, the lateral arm 45 extends less than 10% of the entire distance across the bottom of the shell 5.

Referring now to FIGS. 6 and 7 , the illustrated annulus 25 is similar to that shown in FIGS. 4 and 5 , but the annulus 25 additionally includes an annular plate 50. The annular plate 50 extends around the inner circumference of the shell 5 or in segments extending around portions of the inner circumference of the shell 5. The annular plate 50 is embedded into the foundation 10. The annular plate 50, in vertical cross section, is generally parallel to the lateral arm 45, but extends further toward the centerline 3 of the tank 1 than the lateral arm 45. The annular plate 50 is welded or mechanically fastened (i.e., via bolts or rivets) to the lateral arm 45. In some embodiments, the annular plate 50 and the lateral arm 45 are integrally formed such that the annular plate 50, the vertical arm 40, and the lateral arm 45 are a single piece. The annular plate 50 is formed from steel, or alternatively, similar materials from which the vertical and lateral arms 40, 45 can be formed. The annular plate 50 provides a greater area for the fluid weight 22 to act on the shell 5 than the lateral arm 45 alone. As a result, the addition of the annular plate 50 to the annulus 25 provides even better resistance to seismic uplift than, for example, the annulus 25 as shown in FIG. 5 .

Referring now to FIGS. 8 and 9 , an annulus 25′ is provided on an outside circumference of the shell 5. The illustrated annulus 25′ includes a vertical arm 40′ and a lateral arm 45′ connected by a rolled angle. The vertical arm 40′ extends around the exterior wall of the shell 5 and is substantially parallel to the shell 5 along the centerline 3 (not shown in the detailed views of FIGS. 8 and 9 , but is shown in, for example, FIG. 1 ). The vertical arm 40′ is connected to the exterior wall of the shell 5. The lateral arm 45′ extends from the vertical arm 40′ away from the centerline 3. The angle between the vertical arm 40′ and the lateral arm 45′ is about 90 degrees, although other angles are contemplated.

Since the lateral arm 45′ does not extend under the fluid weight 22, the annulus 25 also includes the annular plate 50 to extend back past the shell 5 toward the centerline 3 and under the fluid weight 22. The annular plate 50 is welded or mechanically fastened (i.e., via bolts or rivets) below, relative to the fluid weight 22, the lateral arm 45′. In other embodiments, the annular plate 50 and the lateral arm 45′ are integrally formed. Similar to the embodiments shown in FIGS. 6 and 7 , the portion of the shell 5 and the annulus 25′ including the annular plate 50 are all embedded within the foundation 10. The pressure from the fluid weight 22 acts on the annular plate 50, which in turn acts on the lateral arm 45′. The lateral arm 45′, via its connection to the vertical arm 40′, acts to better retain the shell 5 within the foundation 10. As a result, the annulus 25′ has a dramatic impact on the tank's 1 ability to resist seismic uplift.

Referring now to FIGS. 10 and 11 , both the annulus 25 and the annulus 25′ are provided. The annulus 25′ is connected to an outside circumference of the shell 5 and is embedded into the foundation 10. The annulus 25 is connected to an inside circumference of the shell 5 and is not embedded into the foundation 10. The lateral arm shown in FIG. 11 has a longest dimension that is much longer than the longest dimension of the vertical arm 40 such that the lateral arm 45 extends under more of the fluid weight 22 than, for example, the embodiment shown in FIG. 5 . As shown in FIG. 11 , the length that the lateral arm 45 extends under the fluid weight 22 is similar to the length that the annular plate 50 extends under the fluid weight 22 in the embodiment of FIG. 7 , and thus provides similar functionality. As a result, the embodiment of the annulus 25 shown in FIG. 11 combines the functionality of the lateral arm 45 and the annular plate 50 into a single structure.

The lateral arm 45 is welded or mechanically fastened (i.e., via bolts, rivets, and/or concrete anchors) to an upper surface 55 of the slab 12, and is not embedded in the foundation 10. Because the annulus 25 is not embedded into the foundation 10, the lateral arm 45 is sealingly (e.g., a water-tight seal) connected to the upper surface 55 of the slab 12. The sealed connection inhibits fluid 20 buildup underneath the lateral arm 45 and the annular plate 50. As a result, the fluid weight 22 acts on the lateral arm 45, which is connected to the shell 5 via the vertical arm 40, to have a dramatic impact on the tank's 1 ability to resist seismic uplift. If the seal were broken, and fluid were to travel under the lateral arm 45, the annulus 25 may be much less effective at increasing resistance to seismic uplift.

Since the annulus 25′ is embedded into the foundation 10, the annulus 25′ is positioned below, relative to a bottom rim of the shell 5, the non-embedded annulus 25. One advantage to the annulus 25 as shown in FIGS. 10 and 11 is that, since the annulus 25 is not embedded into the foundation, the annulus 25 can be added or replaced with less of an impact to the foundation 10. This is especially useful in tanks 1 that, for example, were initially installed with only an annulus 25′, but now require the additional structural support provided by the annulus 25.

Although aspects have been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects as described. 

What is claimed is:
 1. A tank for retaining material, the tank comprising: a foundation for supporting the material; a shell partially embedded into the foundation, the shell configured to retain the material in a material storage area enclosed by the shell; and an annulus connected to the shell, wherein a portion of the annulus extends beneath the material storage area.
 2. The tank of claim 1, wherein the annulus is embedded into the foundation.
 3. The tank of claim 1, wherein, when viewed in vertical cross-section, the annulus includes a vertical arm and a lateral arm, wherein the vertical arm extends along the shell, wherein the lateral arm extends away from the shell, and wherein the vertical arm is connected to the shell.
 4. The tank of claim 3, wherein the lateral arm extends beneath the material storage area.
 5. The tank of claim 3, wherein when viewed in vertical cross-section, the lateral arm extends at about a right angle from the vertical arm.
 6. The tank of claim 3, wherein the annulus further includes an annular plate, wherein the annular plate is embedded into the foundation, and wherein the annular plate abuts the lateral arm and is positioned between the lateral arm and the material storage area.
 7. The tank of claim 6, wherein the annular plate has an outermost diameter that abuts an innermost diameter of the vertical arm.
 8. The tank of claim 3, wherein the shell is generally cylindrical, wherein a curved wall of the shell extends vertically away from the foundation, and wherein, when viewed in vertical cross section, the lateral arm extends from the shell in a direction away from a centerline of the generally cylindrical shell.
 9. The tank of claim 8, wherein the annulus further includes an annular plate, wherein the annular plate is connected to and abuts the lateral arm, and wherein, when viewed in vertical cross section, the annular plate extends from the lateral arm, past the shell, and back towards the centerline.
 10. The tank of claim 9, wherein the annular plate is formed integrally with the lateral arm.
 11. The tank of claim 1, wherein the annulus is a first annulus, wherein, when viewed in vertical cross-section, the first annulus includes a first vertical arm and a first lateral arm, wherein the first vertical arm extends along and is connected to the shell, wherein the first lateral arm extends away from the shell, wherein the tank further comprises a second annulus, wherein, when viewed in vertical cross-section, the second annulus includes a second vertical arm and a second lateral arm, wherein the second vertical arm extends along and is connected to the shell, wherein the second lateral arm extends in a direction away from the shell that is different than the first lateral arm.
 12. The tank of claim 11, wherein the shell is generally cylindrical, wherein a curved wall of the shell extends vertically away from the foundation, and wherein, when viewed in vertical cross section, the first lateral arm extends beneath the material storage area and the second lateral arm extends in a direction away from a centerline of the generally cylindrical shell.
 13. The tank of claim 12, wherein, when viewed in vertical cross-section, the first lateral arm has a longest dimension that is longer than a longest dimension of the first lateral arm.
 14. The tank of claim 1, wherein the annulus is entirely embedded within the foundation, and wherein an interface between the annulus and the shell is entirely embedded within the foundation.
 15. A method of installing the tank of claim 1, the method comprising: connecting the annulus to the shell; and embedding the annulus and a bottom portion of the shell into the foundation.
 16. A tank assembly comprising: a shell enclosing an interior volume; and an annulus, wherein, when viewed in vertical cross-section, the annulus includes a vertical arm and a lateral arm, wherein the vertical arm extends along the shell, wherein the lateral arm extends away from the shell, and wherein the vertical arm is connected to the shell.
 17. The tank assembly of claim 16, wherein the lateral arm extends beneath the interior volume, and wherein, when viewed in vertical cross-section, the lateral arm extends at about a right angle from the vertical arm.
 18. The tank assembly of claim 17, wherein the annulus further includes an annular plate, wherein the annular plate abuts the lateral arm, and wherein the annular plate has an outermost diameter that abuts an innermost diameter of the vertical arm.
 19. The tank assembly of claim 16, wherein the lateral arm extends away from the interior volume of the shell, and wherein the annulus further includes an annular plate, wherein the annular plate is connected to and abuts the lateral arm, and wherein, when viewed in vertical cross section, the annular plate extends along the lateral arm, past the shell, and back towards the interior volume.
 20. A method of installing the tank assembly of claim 16, the method comprising: connecting the annulus to the shell; and embedding the annulus and a bottom portion of the shell into a foundation such that the shell forms sides of an area configured to retain material and the foundation forms a bottom of the area configured to retain material. 